A New York City Police Department slang term for a veteran cop who is a bitter and burned-out complainer, usually an old beat cop who is a shirker.
Some of this information comes from
"Cop Diary -- The Word on the Street -
What a Cop says and how he says it can matter more than his stick or his gun
By Marcus Laffey (from the New Yorker, August 10, 1998"
The rest comes from personal conversations with New York policemen in the 1950s.
The following is from a personal conversation.

They put this old alcoholic hairbag out on the street on a cold New Year's Eve on West 42nd Street near the docks and he's dying for a drink. It's near the end of his shift at midnight. He sees the red lights of a saloon nearby. He starts to edge toward the saloon when he sees a Puerto Rican kid headed toward a fire alarm box on 11th Avenue. Pulling fire alarm boxes in New York on New Year's eve is considered a sport by some. He looks at the saloon. He looks at the kid. The kid pulls the alarm. The hairbag runs puffing over to the kid, grabs him and yells, "Why the hell did you have to go and pull that alarm?"
The kid says, "My house is on fire."

New York City Fireman who doesnt do nothing except, come to work, read the paper, eat meals he didn't help prepare, shit , sleep, wake up and then go home. Usually a fat slob who complains about everything, everybody else is doing. Not realiable when it comes to performing at a fire. Probably is hiding somewhere while everyone else is breaking their ass. And never works on holidays.

GUY #1 : Man, that Charlie is one hell of a hairbag.
GUY #2 : Yeah, we should put him in the bucket and drop him.